As has been mentioned above, the problem has always existed of constructing an adequate means for lifesaving of persons at sea in case of shipwreck. Up to the present time the usual means of rescue consists of boats or rafts of various sizes and designs; these all have the problem of their stability in high seas and hence of the safety of their occupants, whose chances of rescue are considerably reduced in rough weather, in addition to the discomforts entailed in the use of such lifesaving equipment, for their occupants are exposed to the atmosphere and the elements, as well as to the lack of adequate provisions for subsistence, for when disaster strikes no one provides such rafts with the minimum requirements for survival.